Movable partitions are utilized in numerous situations and environments for a variety of purposes. Such partitions may include, for example, a movable partition comprising foldable or collapsible doors configured to enclose or subdivide a room or other area. Often such partitions are utilized simply for purposes of versatility in being able to subdivide a single large room into multiple smaller rooms. The subdivision of a larger area may be desired, for example, to accommodate multiple groups or meetings simultaneously. In other applications, such partitions may be utilized for noise control depending, for example, on the activities taking place in a given room or portion thereof.
Movable partitions may also be used to provide a security barrier, a fire barrier, or both a security and a fire barrier. In such cases, the partition barrier may be configured to automatically close upon the occurrence of a predetermined event such as the actuation of an associated alarm. For example, one or more accordion-type folding or otherwise extending movable partitions may be used as a security barrier, a fire barrier, or both a security and a fire barrier wherein each partition is formed with panels connected to one another with hinges. The hinged connection of the panels allows the partition to fold and collapse into a compact unit for purposes of storage when not deployed. The partition may be stored in a pocket formed in a wall of a building when in a retracted or folded state. When the partition is deployed to subdivide a single large room into multiple smaller rooms, secure an area during a fire, or for any other specified reason, the partition may be extended along an overhead track, which is often located above the door in a header assembly, until the partition extends a desired distance across the room.
In some applications, the header assembly may provide structural support for the overhead track, the movable partition, and a motor. In fire barrier applications, it may be necessary that the movable partition and the header assembly of the partition provide a degree of resistance to fire. Generally, a fire barrier system or assembly provides a barrier to fire, smoke, and heat. Thus, a fire barrier may retard or resist the deleterious effects of fire, smoke, and heat for a certain period of time. A number of standardized tests that evaluate the effectiveness of fire barrier assemblies have been developed for use in the building industry. These are published, for example, in the Uniform Building Code (UBC), the International Building Code (IBC), and by the National Fire Protection Association (NFPA), UNDERWRITERS LABORATORIES® (UL), and the American Society for Testing and Materials (ASTM), among others. Various agencies test fire barriers using these standardized tests, and assign ratings to fire barriers that indicate their effectiveness at slowing the progress of a fire. Barrier testing agencies include Intertek Testing Services, UNDERWRITERS LABORATORIES®, Chiltern International Fire, Ltd., and Warrington Fire Research, among others. Ratings of fire barrier assemblies are generally provided in minutes, and typically vary from 20 minutes to 180 minutes. Examples of fire barrier assembly standards and testing methods can be found in UNDERWRITERS LABORATORIES® UL 10B document titled, “UL Standard for Safety Fire Tests of Door Assemblies.”
To provide a fire barrier, the header assembly along with the movable partition and surrounding walls must also provide some level of fire resistance in addition to the movable partition. Thus, when the partition is employed as a fire barrier, it is known to attach the movable partition to a header structure that is configured to provide resistance to fire. FIG. 1 illustrates an example of a conventional fire-resistant header assembly. A header assembly 10 is provided in a header space 12 formed between two fire rated walls 14, which include an opening for the movable partition (not shown). The header assembly 10 includes rods 16 extending from a structural support 18 provided above the two fire rated walls 14. The rods 16 extend from the structural support 18 to a location proximate an overhead track 20 provided for the movable partition. Layers of plywood 22 are attached to the rods 16 extending from the support structure 18. The layers of plywood 22 are typically custom fitted onsite during installation of the movable partition and extend longitudinally along the length of the movable partition and the overhead track 20. The layers of plywood 22 also extend laterally across the header space 12 to the two fire rated walls 14. Layers of gypsum board 24 are provided between the overhead track 20 and the layers of plywood 22. The layers of gypsum board 24 also extend longitudinally along the length of the movable partition and the overhead track 20 and extend laterally across the header space 12 to the two fire rated walls 14. Some of the layers of gypsum board 24 extend only partially across the header space 12 in a lateral direction in order to provide a pocket for the overhead track 20. That is, some layers of gypsum board 24 extend longitudinally along a lateral side of the overhead track 20 and extend laterally between a lateral side of the overhead track 20 and one of the two fire rated walls 14. The layers of gypsum board 24 (together with the layers of plywood 22 and the overhead track 20) provide a fire-resistant barrier extending across the header space 12.